Gazprom said on Wednesday it could demand advance payments from Kiev for gas but President Putin said the company should hold off, pending talks with "our partners" - widely believed to mean the EU.

In a letter to European leaders, President Putin warned that the "critical" situation could affect deliveries of gas to Europe, his spokesman Dmitry Peskov said.

The letter released by the Kremlin says that if Ukraine does not settle its energy bill, Gazprom will be "compelled" to switch over to advance payment, and if those payments are not made, it "will completely or partially cease gas deliveries".

Mr Putin adds that Russia was "prepared to participate in the effort to stabilise and restore Ukraine's economy" but only on "equal terms" with the EU.

And he says that while Russia has been subsidising the Ukrainian economy with cheap gas, Europe has been exploiting its raw materials and worsening its trade deficit.

The US state department later said it condemned "Russia's efforts to use energy as a tool of coercion against Ukraine".

Spokeswoman Jen Psaki said the price Ukraine was being charged for its gas was "well above the average price paid by EU members".

Nearly a third of the EU's natural gas comes from Russia.

Previous Russian gas disputes with Ukraine have led to severe gas shortages in several EU countries. The EU says it has extra gas supplies and reverse-flow technology to deal with any such disruption now.

Buildings occupied

In Kiev, the authorities said Ukraine would not prosecute pro-Russian activists occupying official buildings in Donetsk and Luhansk if they surrendered their weapons.

The separatists in the east - a mainly Russian-speaking region with close ties to Russia - are demanding referendums on self-rule. In Donetsk they have declared a "people's republic". Gunmen have been seen among the protesters in Luhansk.

Ukraine has accused Russia of stirring up the unrest, a claim Moscow denies.

Meanwhile, Nato has unveiled satellite images it says show some 40,000 Russian troops near the Ukrainian border in late March and early April, along with tanks, armoured vehicles, artillery and aircraft.

British Brigadier Gary Deakin, speaking at Nato military headquarters in Belgium, said it was a force that was "very capable, at high readiness, and... close to routes and lines of communication".

A Russian military officer said the images dated from August last year and denied there had been a build-up of troops along the border, Russia's Ria Novosti news agency reported.

Several satellite images have been released by the Supreme Headquarters Allied Powers Europe of the Russia/Ukraine border areas. This photo, which Nato says was taken on 22 March, appears to show Russia's elite Spetsnaz forces stationed at Yeysk in southern Russia, near the border

This image purports to show a Russian artillery battalion at a military base near Nonocherkassk, east of the Sea of Azov in southern Russia

This apparently shows Russian tanks at a base near Kuzminka on 27 March

Ukraine fears that the Russian separatist actions are a provocation similar to the protests that gripped Crimea days before Russian troops annexed the peninsula last month. Russia denies the claim.

President Putin said on Thursday his decision to annex Crimea was taken after secret opinion polls and had not been planned in advance.

Speaking to political supporters near Moscow, he said the first poll showed 80% of the Crimean population wanted to join Russia. He said he had not made any decision until it was "clear what the mood of the people was".

Russia, the US, Ukraine and the EU are to hold talks in Geneva next Thursday to try to resolve the impasse, EU diplomats have said.

They will be the first four-way talks since the crisis began.

Russian Foreign Minister Sergei Lavrov told US Secretary of State John Kerry by telephone on Wednesday that the meeting should focus on fostering dialogue among Ukrainians and not on bilateral relations among the participants.

In another development, the Kremlin announced that President Putin had sacked 14 generals. They were sacked from the emergencies ministry and prison service, as well as regional branches of the interior ministry and the Investigative Committee (Russia's equivalent of the FBI).

It was not immediately clear if the move was a routine step. Russia has some 800 generals in its army alone.

Comments

Comment number 1111.

DavidB10th April 2014 - 22:56

Boyers 1100You should stand for Ukrainian Presidential election,I'm sure the EU/US would sponsor you, you seem to advocate their thinking. May I suggest You have a word with Ms Nuland Im sure she will use her influence to assist you. Sashka Biley could be your running mate,oh sorry he shot himself,not to worry I'm sure they can arrange for another thug for the roll

Comment number 1110.

Rick10th April 2014 - 22:55

1104.

You're cynical. From what I could see there were no guns pointed at anyone. Where's your photographic proof? Call me cynical but the West seems to find democratic voting illegal when it restores the USSR and is happy to endorse right wing thugs in ski masks with clubs smashing their way into government buildings as democratic when it's dismantling the USSR. And we have plenty of evidence.

Comment number 1109.

Dave150610th April 2014 - 22:55

"1083.Angel-Alice 13 Minutes ago The US sends another war ship to Russia's Black Sea coast"

It will be interesting to see if the ship has an explosion and a clearly labelled piece of Russian hardware will be seen hanging from the ship so that the NATO articles can be invoked for war just like the USS Liberty.

Comment number 1108.

historical10th April 2014 - 22:54

Putin is only doing this in retaliation to Obama closing McDonalds in Crimea.No seriously, the west needs to put its money where its mouth is and having backed the Coup in the Ukraine, it now needs to bail the country out to stop the Ukraine falling in to civil war.

Comment number 1103.

Dejan10th April 2014 - 22:49

Nobody can expect that Russia pays 38 billion $ from 2009 in different subsidies to Ukraine and not to be interested for political processes there. Russia delivers gas completely according to contract signed by Julia Timoshenko and after approved different discounts and benefits to support Ukrainian economy. Cheapest gas with price of 238 $ per 1K m3 has been delivered to Ukraine, but not paid.

Comment number 1102.

jim27210th April 2014 - 22:48

@1097 Scott0962

1) Russia had no problem signing a pact with the Nazis to divide Poland between them.

We don't continue to hold "the war" against the Germans or the many European nations that allied themselves with the Nazi's at the time so why would we now bring up 70 year old history against the Russians?

Comment number 1100.

Boyers10th April 2014 - 22:43

You begin to see why UKIP and that pathetic idiot Farage supports Putin - both are fascists. It is time to terminate UKIP and their ridiculour policies - according to Farage Putin is his hero - he is nothing less than a criminal, doing what Russia always did - bullying other nations and invading sovereign land. To hell with Rissia and to hell with that monster Putin.

Comment number 1098.

Murad10th April 2014 - 22:42

Ukraine refuses to pay even twice discounted price for gas. It prefer to still from transit for EU and blame Russia., who does just business, no politics. But strategic goal of EU action is to press Ukraine to hold the payment thus force Russia to cut gas supply, then later convince all Europeans :Look Russia starts energy war with EU!!!!'. This is European modern policy.

Comment number 1097.

Scott096210th April 2014 - 22:42

re. 1015.Angel-Alice 1) Russia had no problem signing a pact with the Nazis to divide Poland between them.2) No, Putin didn't send troops to Crimea, those masked, armed men in uniform without insignia were bandits and hooligans.3) That "fair referendum", illegal under international law, was monitored by observors hand picked by the Kremlin to read Moscow's script.

Comment number 1094.

G-425Comment number 1094 is an Editors' Pick10th April 2014 - 22:41

The core problem is reliance on 19th century energy sources in the 21st century. The future is nuclear fission + renewables, and then conversion from uranium to thorium as fission fuel. That gets us a few hundred years easily, during which time fusion will become commercially viable.

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